My 2002 Mustang GT has a left turn signal that flashes twice as fast as the right turn signal. Just guessing I would say that it's a flasher relay that needs to be replaced - does that sound right? I assume there is a separate relay for each side, if this is anything like a 30 year old GM product....any help guys? thanks in advance!

 

Sounds like you have a burnt out bulb in the left tail lights. It's Ford's version of a bulb out warning.

 

so is there more than one bulb back there? I checked and all the lights seemed to work.

 

There are 4 bulbs in each tail light housing, 3 for brake/turn, and 1 for back-up. The 3 brake/turn bulbs are 3157, which means they are dual filament. You'll need to turn on the parking lights, check the lights, then turn on the emergency flashers to check the lights to see which bulb/filament is out.